Low BTSCC year around? Oh yes you can!

Are you a control freak or are you of the mind to live
and let live? Well, when it comes to holding bulk tank
somatic cell counts (BTSCC) in check this summer we hope
you are a mastitis control freak!

Everybody knows that BTSCC increases during the summer.
The average BTSCC increase on Minnesota herds during the
summer months is approximately 75,000 to 100,000 higher
than the cooler months of the year. In fact, we have come
to accept it as an unalterable fact. But, does it have
to be this way? Could you do a better job to keep BTSCC
at a low level this summer?

Study of BTSCC records in Minnesota dairies well known
for their ability to maintain low BTSCC year around demonstrate
it is possible. One striking feature that distinguishes
these dairies is a very low day-to-day BTSCC variation, ranging
from only 10-20,000 BTSCC. This is outstanding! These dairies
can be characterized by a single word... consistency.
Equipment is always clean and functioning properly, personnel
follow established procedures carefully, and the cows are
clean (especially teat surfaces) year around. We are not
surprised by this observation. Several University studies
in the U.S. and Europe have verified that this is true.

There has been a lot of recent
talk about the changing mastitis pathogen profile these
days. Some are saying, "things
are not what they used to be and maybe that is the problem." It
is true that things have changed. Today environmental mastitis
pathogens (Coliforms and environmental streps) account
for most clinical and subclinical mastitis on dairies.
Based on University of Minnesota Udder Health Lab data,
80% of all mastitis cultures during 2000-2003 indicated
an environmental pathogen origin (see chart). Several years
ago, Ohio State researchers found that 82% of all clinical
cases in 9 modern freestall dairies were caused by environmental
bacteria. This is especially true during the summer months
where they found exposure to environmental pathogens very
high in bedding.

During the summer, bacteria grow
at rates 300-500 times faster than during the cold winter
months (40° F or
less). During the summer wherever the cow lies down, bedding
or pasture surfaces can be teaming with bacteria. Unless
we take aggressive management steps to minimize exposure,
teat surfaces will be contaminated with lots of environmental
bacteria, many of which are mastitis pathogens. Both the
cow's hygiene and cleanliness of the cow's
environment are much more important during summer than
during winter.

It is worth reminding ourselves that whatever is on teat
surfaces needs to be removed prior to milking or the risk
of creating a new mastitis infection increases dramatically.
A routine (monthly) bulk tank bacteria culture is an excellent
means of gauging how well you are doing. High levels of
the environmental bacteria in the bulk tank milk indicate
that you need to be doing a better job at pre-milking cow
prep or bedding management. In fact you need to do A
LOT BETTER during the summer to have the same
effect as during winter.

With the warm summer months now upon us, are you ratcheting
up your mastitis control or are you letting the bacteria
take charge? What exactly do you need to do? We suggest
the following:

Milking procedure

Work consistently harder. Remove all
dirt and manure from all teat surfaces prior to each
milking. You will be amazed at what just 5 seconds more
prep time could do.

Be sure that the pre-dip coverage is excellent (covering
the entire teat surface) and that the pre-dip contact
time is at least 30 seconds before you wipe the teat
dry. The pre-dip must be in physical contact with the
bacteria long enough to kill them.

Make an extra effort to dry the teat surfaces
including the teat end.

Bedding management

Bed stalls more frequently. Clean
and re-bed the back one-half of every stall every day
when using organic bedding (sawdust, straw, etc). Once
every week sweep all the bedding out of the stall and
start over. Even when using inorganic bedding like sand,
application of fresh clean sand should be more frequent
during the summer months. Periodically all the used sand
will need to be removed.

What about those dry cows? What is
their environment like? You can do a bedding culture
to see what teat exposure there is. Dry cows are particularly
vulnerable to highly contaminated bedding materials.

Ventilation

Housing facilities need good ventilation not
only to reduce heat stress but to keep bedding surfaces
dry. Bacteria require moisture to grow so if you deprive
them of this critical nutrient they cannot grow.

Cow hygiene

Clean cows have lower SCC.

U of MN research shows that cleanliness of lower rear
legs and udders correlates to individual cow SCC.

Each one unit improvement in cow hygiene score will
result in a 40-50,000 SCC reduction.

Cow health factors

Reduce heat stress since
it will depress the cow's immune system.

Feed cows balanced diets and minimize
depressed feed intakes especially during the dry period
and early lactation. A negative energy balance will decrease
immune system function making cows more susceptible to
getting new mastitis infections.

Keeping BTSCC lower than 200,000 is possible year around.
It will take at little more consistent effort during the
warm months of the year but it is well worth it. For more
detailed information, visit the dairy extension web site
(www.extension.umn.edu/dairy)
and click on "Quality Counts."